gridlock61

I thought I saw a thread about this a couple of months ago, but could not find it. My manual tranny on my 993 will most probably need to be rebuilt, as its a bit difficult shifting, and feels like it may need some new synchros. What is a reasonable price range on having a shop do the work from start to finish replacing all the synchros. One shop I spoke to mentioned that the engine and transmission will need to be removed from the car, then the transmission separated from the engine.

Also, what other items should be replaced at this point? Clutch? Flywheel? What are the costs for a new clutch and flywheel? What about going with a mid-weight flywheel instead of stock? Is it much more expensive?

By the way, my car is a '95 Cab.

Thanks

ca993twin

Before you spend big bucks on a transmission rebuild, have you done a flush of the fluid with some of the superior products recommended on this forum (I forget... Redline? Motul? Mobil One?). Many people report much improved shifting with a simple change. How many miles on your car? The transmissions are VERY robust, and unless abused, it takes a LOT of hard driving to hurt them.
Have you considered if your clutch is fully disengaging? Clutch hydraulics, pedal bushings, and clutch fork can also cause hard shifting.
The transmission can be removed from your car without taking out the engine. With the transmission out, the clutch should be inspected and most likely replaced just because you're in there. A change of flywheel is a matter of taste, and a mid-weight might be a good choice for a 1995 car.

gridlock61

Thanks for the response.

I have already replace the transmission fluid with Rennline, and unfortunately it didn't make a difference in shifting quality. The car has about 52k miles. It's possible something else is wrong, and the mechanic will check it out, but he thinks based on previous times he's driven the car, that it's an internal transmission issue.

Is it easier to remove the transmission along with the engine? Not sure then why the mechanic suggested removing the engine along with the transmission first.

Cemoto

I'm no expert here, but I don't think I'd trust a gearbox rebuild to a mechanic who says you need to drop the motor to pull the transmission.

How many has he done?

I'm in agreement with Steve, I'd chase something other than the gearbox first, maybe the clutch slave cylinder.

You just got this car from Richard Sloan a few months back. If the transmission does need a rebuild, I think I'd be giving him a call and see what he has to say.

Regards,

Steve Weiner-Rennsport Systems

JMHO,....

52K seems awfully soon to rebuild one of these transmissions unless its been subjected to abuse. If it were my own car, I would flush the clutch hydraulics and if the fluid came out brown (it usually does), I would replace the slave cylinder before doing anything else.

Hard shifting can be caused by:

1) Worn syncronizers, operating sleeves, dog rings, etc.

2) Faulty slave cylinder.

3) Rusty transmission input shaft causing the disc to hang. Not uncommon on low-mile cars that sit around too much.

4) Worn clutch release fork & bearings.

5) Using the wrong transmission oil.

The transmission can be successfully removed in the 2WD cars with the engine in place. The technician must be VERY careful not to put any side load on the input shaft when extracting and installing the gearbox otherwise a bent input shaft is the result.

I hope this helps a little bit,

gridlock61

Not sure how many he's done, but he is known on this forum. I would give Richard a call, but based on my experience with him, I'm very doubtful he would pay anything to look at the problem, let alone spend any time with it.


Thanks for the info. Based on what you and others have mentioned, I will have them (or someone else) take a closer look before taking apart the transmission. One thing they did mention when they changed the transmission oils recently, was that the old fluid was quite gray looking, and may have never been changed before. The new oil is a commonly recommended Rennline oil, but unfortunately made absolutely no difference. The transmission gets more 'sticky' and hard shifting the colder it gets outside, and before the engine/transmission has fully warmed up. Does this offer any additional clue as to what may be wrong?

What does a new slave cylinder cost, and what is the labor involved in replacing it?

By the way, I've only owned the car since August of this year, so have no idea what kind of life it led prior to that (I do have some service history, which seemed fairly normal, but didn't notice a transmission oil change).

JasonAndreas

Yes, they are using the wrong fluid for cold weather. You want Mobilube PTX from a Porsche dealership. Not SHC, Delvac or LS. How is your shifting once everything is upto temperature? Is there a specific gear that you have trouble with or is it all of them?

uscarrera

gridlock61 if you decide to get into box mechanic should diffenitly be able to do without engine removal if you are going to do clutch and flywheel I would op for engine removal makes it easier and more complete. Just as a heads up when I did the box in my race car kept all stock parts so before you buy any gears, forks etc. let me know I might have the part collecting dust somewhere in garage and better it help out a fellow 993er than as a dust collector
Rich

chsu74

Take it to another shop for a 2nd opinion. There is a good shop near you and another near Woodbury Commons shopping center, NY

stace

to answer your question the clutch slave is less than $100 in parts and is a DIY without removing the engine or tranny. I would also replace the flex hose attached to the slave. it made a big difference in how smooth my car shifts. also just to be sure; are you positive the shift linkage is in good condition. the linkage on these cars has a couple of nylon bushings which can fall apart. also cheap to fix and takes just a few minutes to check.

if you do rebuild the tranny - time for a regearing as well? lots of good advice on here about that!

good luck!

ca993twin

Here is the best of the Rennlist spirit! Rich... you da man!

gridlock61

Thanks everyone for all the information. I brought the car back to have them check things over again. I also had them install FD SSK and Goldenrod (which I wanted to to anyhow) to see if that helped in any way, and does make the shifting more precise, but didn't help the recalcitrant shifting much. They checked the clutch operation, master and slave cylinders, and replaced the transmission fluid again (they changed it several months ago, at which point they found a lot of metal and a very grayish color).

Although it still is possible there is something going on with the clutch, their feeling (and I tend to agree) is that there are probably worn synchros. My guess is that the prior owners may have beat on it and never changed the fluid, which resulted in lots of metal in the fluid and worn synchros. It's not so bad as to be un-drivable, and is much worse in cold weather, but I'll pursue it further down the road a bit. The thought now is if it does need rebuilding, should I go all the way and change the gear ratios?! A LOT more money, but I'm sure worth it in the long run.

gridlock61

Much appreciated! Not sure what am doing at the moment, but thanks much for the offer.

Martin S.

No such thing as reasonable when you do a transmission, in my experience. Let me cut to the chase…just be prepared to write a check at a minimum of $6,000, to $10,000 + I have done the research, and as most of us have found out, there are no short cuts to rebuilding a Porsche Gertag transmission. And keep in mind that Porsche parts seem to have gone through the roof price wise.

And there is the "while you are in there" factor, might as well replace the clutch and throw out bearing. And "while you are in there", might as well upgrade to forged shifting forks (There are two, about $700 for both). And those pesky brass synchros, you'll need at least three, maybe four @ $300 a pop, internet pricing. Want that dream close ratio transmission that owners say make the car feel as if it has about 50 HP more than stock? You'll need at least three gear sets at $1,200 each…consolation, you can make current 5th, your new 6th and save $1,200. Also note, these are aftermarket gear sets, factory gear sets can be 50% more.

One other factor to consider, if the transmission has been worked on before, your super transmission tech may find screw ups that the previous mechanic imparted, and will need fixing.

Rebuilding a transmission can be rationalized just as a divorce, "It costs so much, because it's worth it!"